"For nearly two decades I've grasped for a connection to my family's African heritage. I grew up in an ethnically diverse, Northern New Jersey suburb where many of the black students were first-generation Americans or recent immigrants with ancestry from countries like Nigeria, Ghana and Senegal. Now in my late 20s, I've decided to delve into my family's genetic lineage with genealogy tests and research. My maternal line survived slavery in Southeastern North Carolina, and while there are certainly several white men in the family tree, we've never known of any white women.

"Several months ago I received my African Ancestry Matriclan DNA test results with the expectation that my maternal line would trace back to one of the powerful West African nations heavily involved in the slave trade. Instead, my results showed a direct match for haplogroup U6a1 -- a European lineage. I was disappointed and thoroughly confused. It felt as though I'd never find the African connection I'd sought since childhood.

"After countless hours combing the Internet for more information about my fellow U6a1 descendants, I found the haplogroup is quite common in North African countries, such as Morocco. The possible North African connection only intensified my confusion and leaves me with more questions than ever." --Kristin Rodney

Your confusion is not surprising. Discussions over whether the haplogroup U6 (also called "Ulla") should be considered European or African have actually been going on for some years now. Although the testing service African Ancestry designated U6a1 as European, as you discovered, the haplogroup actually appears throughout a vast geographic area from the Iberian Peninsula in the North to Kenya in the South, and from the Canary Islands in the West to Syria and Ethiopia in the East.

The U6a1 subgroup seems to show the migration of peoples out of Maghreb (Northwest Africa) through East Africa into the Near East and back again. According to its FamilyTreeDNA project, "The U6 haplogroup has a Southwestern Asia origin approximately 40,000 or 45,000 years ago. The early Upper Paleolithic carrying U6 return to Africa from the Mediterranean area." This return to Africa was about 30,000 years ago during Paleolithic times.

As this all occurred so long ago that choosing whether to consider this line European or African becomes more a matter of perspective. On the one hand, the line originated in Africa, but so did every population. This subgroup has also primarily been found in Africa for many thousands of years. On the other hand, what makes it different from other African-based haplogroups are changes that evolved out of the time spent in the Near East and on the migration back to Northern Africa.

Your female ancestor from whence the U6a1 haplogroup stems lived so long ago that there are any number of possible ways in which your line ended up in North Carolina. It could be that your ancestors were among those who migrated to Europe and/or became explorers traveling even as far as the New World. Or, your ancestors could have been taken directly from Northern Africa as slaves.

The Barbary/Berber Coast (including Morocco, Algiers, Libya and Tunisia) held a thriving slave trade throughout the peak centuries of the transatlantic slave trade. This was partly due to the raiding by the Barbary pirates but stemmed from the tradition of the Arab slave trade already in place since about 650 A.D. Those sold in this area were not just black Africans but also white Europeans from as far north as the United Kingdom. Eventually, in the early part of the 19th century, this practice was stopped through military action on the part of the young United States of America and European nations like Great Britain and the Netherlands.

To escape the Inquisition, Muslims from the Iberian Peninsula (who usually identified as Portuguese) returned to North Africa and sailed off to explore new lands. They were also captured as slaves and sent to Spanish colonies. These ancestors could then have mixed with the native populations and moved around the New World. At some point in time, it is possible that the union of an African man and a European woman introduced the U6a1 haplogroup into your lineage.

I spoke with the historians John Thornton and Linda Heywood, who offered some alternate theories of how you might have come by the U6a1 haplogroup.

"During the 10th and 11th centuries, a good number of North African nomads speaking Berber languages moved back and forth across the Sahara. Early Arab geographers like al-Bakri (1068) give some details about this movement, and then, about a century later, a number of Arabs from the Arabian peninsula invaded North Africa, and many Berbers fled south into the desert as refugees. These groups were often active in the Saharan trade, again as documented by medieval Arab geographers. It is possible that one of these groups or families of them took up residence in West Africa and intermarried with local people.

"Another possibility would be via the Moroccans who invaded Songhay in 1591 with Judar Pasha. These troops operated around Timbuktu and the bend of the Niger River, and their activities in the 17th and 18th centuries are extensively documented in a local chronicle called 'Tedzkirat en-Nisian.' But Morocco's invasion of Songhay was only one well-documented wing of Moroccan expansion; another was directly south in the region north of the Senegal Valley, where contemporary sources often called the participants 'Ormans.' They are associated with raids on the countries to the south, and some of the groups occupied areas on the border between the desert and the thoroughly cultivated regions on a permanent or semi-permanent basis.

"While these Moroccans are represented as raiders, they did not always win every battle; in fact they often lost, and counterattacks from districts like Futa Tooro, the Wolof kingdoms and the Bambara kingdoms of Kaarta and Segu often engaged Moroccans. In the course of these wars and engagements, Moroccans, including women, are quite likely to have been enslaved." Perhaps your female ancestor with the U6a1 haplogroup was one of these women.

So as you see, there are a number of ways in which you might have ended up with the U6a1 haplogroup. What you should also keep in mind is that this haplogroup forms only one of the many branches of your ancestry. There are numerous ways in which you and your future children can continue to learn about all aspects of your family history.

Henry Louis Gates Jr. is the Alphonse Fletcher University Professor and the director of the W.E.B. Du Bois Institute for African and African-American Research at Harvard University. He is also editor-in-chief of The Root. Follow him on Twitter.

This answer was provided in consultation with Kyle Hurst, a researcher from New England Historic Genealogical Society. Founded in 1845, NEHGS is the country's leading nonprofit resource for family history research. Its website, AmericanAncestors.org, contains more than 300 million searchable records for research in New England, New York and beyond. With the leading experts in the field, NEHGS staff can provide assistance and guidance for questions in most research areas. They can also be hired to conduct research on your family. Learn more today.